Process for sterilizing filters.



E. ZAHM.

PROCESS lFOR STERILIZING FILTERS.

APPLICATION FILED MAY 6, 1911.

Patented Apr. 16, 1912.

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E. ZAHM@ PROCESS POR STERILIZING FILTERS.

APPLICATION FILED MAY 6, 1911. 1,023,488, v Patented Apr. 16, 1912.

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E. ZAHM.

PROCESS FOR STERILIZING FILTERS.

APPLICATION HLBD MAY 6, 1911.

Patented Apr. 16, 1912.

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COLUMBIA PLANDURAPH co WASH NaToN n c EDWARD ZAHlVI, OF BUFFALO, NEW YORK.

PROCESS FOR STERILIZING FILTERS.

Specification of Letters Patent.

Application filed May 6, 1911.

Patented Apr. 16, i912. Serial No. 625,590.

T0 all whom if may concern.'

Be it known that I, EDWARD ZAHM, a citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Processes for Sterilizing Filters, of which the following is a specification.

This invention relates to a process for sterilizing filters generally and particularly filters containing one or more hollow filtering cores of porous material.

The object of this invention is to provide a process whereby these cores may be thoroughly sterilized and mounted in the body of the filter with a minimum possibility of contamination.

In the accompanying drawings consisting of 3 sheets: Figure 1 is a vertical longitudinal section of the sterilizing tank in which a plurality of filtering cores are mounted for sterilization by means of hot water. Fig. 2 is a tcp plan view thereof. Fig. 3 is a vertical longitudinal section of a lter embodying my invention. Fig. 4 is a longitudinal section of one of the filtering cores or cells, on an enlarged scale, and showing one form of closure for the out-let of the cell or core. Fig. 5 is an end elevation of the same. Fig. 6 is a fragmentary longitudinal section of a filtering core showing a slightly different form of closure from that shown in Fig. 4.

Similarletters of reference indicate corresponding parts throughout the several views.

The casing of the filter shown in the drawings for illustrating my process comprises a cylindrical body or wall l which is preferably so arranged that its axis is hor izontal, a vertical transverse partition 2 arranged within the cylinder between the front and rear ends thereof and provided with a plurality of horizontal openings 3, a front cover or head 4 detachably secured to the front end of the body and a rear head or cover 5 detachably secured to the rear end of the cylinder. By this means a front or inlet chamber 6 is formed within the cylinder between the partition and the front head and a rear or outlet chamber 7 is formed between the rear side of the partition and the rear head. The liquid to be filtered is introduced into the inlet chamber by means of a pipe 8 and the filtered liquid is delivered from the outlet chamber by means of a pipe 9.

10 represents a plurality of filtering cores or cells through which the liquid passes on its way from the inlet chamber to the o utlet chamber and whereby any suspended matters are separated from the liquid. Each of these filtering cells or cores is preferably constructed of porous material in the form of a tube which is closed at its front end by an integral bottom 11 made of the same material as the body of the core while its opposite or rear end is provided with a head 12, preferably of metal. The head 12 has a rearwardly projecting contracted neck 13 of the same material. These filtering cores are arranged horizontaly within the inlet chamber and the neck of each core projects rearwardly through one of the openings in the partition. These necks are secured in these openings so as to form a liquid tight joint between the same and thereby prevent leakage through this joint from the inlet to the outlet chamber. This joint is preferably produced by placing a gasket or washer 14 of rubber or similar Y flexible material around the front end or base of the neck between the front side of the partition and the head of the core and compressing this gasket between this head and the partition by drawing the neck rearwardly. This rearward movement of the neck is preferably produced by means of a clamping screw nut l5 applied to the externally threaded rear part of the neck and bearing against the rear side of the partition by means of an interposed washer 16 which is preferably constructed of metal.

Upon introducing a liquid under pressure into the inlet chamber of the lter the same is forced through the pores of the cores into the interior thereof and during this passage of the liquid any impurities contained in the liquid are separated therefrom and retained on the outer side of the cores. The filtrate passes from the interior of the cores rearwardly through the necks thereof into the outlet chamber and is then delivered from the latter by means of the discharge pipe 9 to the place of consumption.

In order to obtain a filtrate of maximum purity it is necessary for the joints between the necks of the cores and the partition to be perfectly tight and that the cores are also free from cracks, fissures or flaws which otherwise would permit the passage of unfiltered liquid from the inletchamber to the outlet chamber. For the purpose of readily and reliably testing the filter for determining whether any of the filtering cores are defective or any of the joints between the necks thereof and the partition are not tight, means are provided for temporarily closing each one of the necks at the rear or outlet end thereof. This closure may be effected by various means, for instance, as shown in Fig. f1, this closure consists of a screw plug 17 having an external screw thread which engages with an internal thread at the rear end of the neck and a packing ring 18 of rubber or other material interposed between a shoulder on the head 19 of t-he plug and the rear end of the neck. 1f desired, this closure may be effected by the means shown in Fig. 6 which consists of a stopper 2O having a facing 21 of rubber or similar elastic material which is adapted to engage frictionally with the smooth bore at the rear end of the neck. Preparatory to testing a filter all of the necks of the cores are closed at their rear ends. Upon now introducing liquid under pressure into the inlet chamber while the rear head of the outlet chamber is removed this pressure is brought to bear more heavily against the joints between the necks of the cores and the openings in the partition and if any of these joints should leak this can be readily observed and located by the operator on the rear side of the partition so that the necessary tightening of any leaky joint can be effected or a new core substituted for correcting such leakage. By removing one or more of the closures of the necks of the cores at a time the operator can also determine by the amount or condition of liquid which is discharged from the necks of the uncovered cores whether the amount of liquid so discharged or the condition of the liquid is normal. Excessive discharge of liquid from the neck of a core indicates that the core is either cracked or fissured or contains some other flaw which permits unfiltered liquid to reach the inner side of the same from the inlet chamber in which case the defective core is discarded and replaced by a perfect one. It will be apparent that by this means the operator is able to determine with facility whether or not the filter is in normal working condition and operating with the greatest efficiency.

Prepartory to mount-ing the cores on the casing or support of the filter the same are sterilized by the following means and retained in a perfect sterilized condition until they are mounted on the filter casing or support: 22 represents an open top tank filled with water in which the filter cores are immersed and boiled until sterilized. Any suitable means may be provided for boiling the water for sterilization so that the germs contained in the same as well as any germs on articles immersed in the same will be destroyed, for instance, steam conducting coils 30 arranged in the lower part of the tank, as shown in Fig. 1. A plurality of hangers or racks are arranged side by side above the tank, each hanger having a depressed central horizontal bar 23 which is arranged in the upper part of the tank and two elevated laterally projecting arms Y 211 arranged at opposite ends of the bar and secured to the upper edges of the transverse walls of the tank by means of clamping bolts 25, as shown in Figs. 1 and 2, or by any other suitable means. The depressed supporting bar of each hanger is provided with a longitudinal slot 26. From each of the supporting bars is suspended a row of the cores by arranging the neck of each core within the slot 26 of the supporting bar and engaging the clamping nut 15 of the respective neck with the upper side of this bar. The cores are suspended in this manner within the water of the tank while the latter is boiled a sufficient length of time to destroy all bacteria `which may be present on the exterior or interior of the cores and the part-s connected therewith. After the cores have been thus sterilized and while the same are still submerged in the sterile water of the tank the upper or outlet ends of their necks are closed by the plugs 17 or equivalent device so as to seal the sterile water contained within the cores. The water within the tank may now be allowed to cool sufficiently to permit the operator to handle the cores and remove the same from the tank and hangers to the filter casing. It is preferable, however, for the purpose of expediting the handling of the cores, to cool off the hot water in the tank by running in cool sterile water so as to cool the liquid sufficiently to permit handling. After the cores have been thus cooled and while the necks thereof are still plugged the same are removed from the hangers or racks and secured by their necks in the openings of the partit-ion of the filter body. Just before closing the rear end of the cylinder of the casing by means of the rear head the plugs are removed from the necks of the cores, thereby permitting the sterile water contained within the cores to escape therefrom and also permit the liquid to be filtered to pass from the inlet chamber through the cores into the outlet chamber. It will thus be noted that by this method of sterilizing the cores they are maintained in the highest state of sterility from the time they are sterilized until they are actually put into operation in t-he filter, thereby obtaining a filtrate of maximum purity.

I claim as my invention:

l. The herein described process of sterilizing a hollow ilter core consisting in immersing the saine in Water heated at a sterilizing temperature, and sealing the opening leading to the interior of said core.

2. The herein described process of sterilizing a hollow iilter core consisting in immersing the same in Water heated at a sterilizing temperature and confining sterilized Water in said core by closing the outlet thereof.

Vitness my hand this 27th day of April, 1911.

EDXARD ZAHM.

Witnesses:

THEO. L. PoPP, ANNA HEIGIS.

Copies of lthis patent may be obtained for iive cents each, by addressing the "Commissioner of Patents,

Washington, D. C. 

